William lewis evans



2 Sheets-Sheet 1.

(No Model.)

W. L. EVANS, Jr. ROTARY STEAM ENGINE. No 552,992. Patented Jan. 14, 1896.

Wi m llz'zaus cf]:

KNDREW 84GRMAMIHOYQUWOYWASNINGTQN. RC.

(NoMode L) 7 2 Sheets-Sheet 2.

, L. EVANS, J1. ROTARY STEAM ENGINE.

I Patented Jan 14, 1896.

UNITED STATES PATENT OFFICE.

W'ILLIAM LEXVIS EVANS, JR,

OF \VASIIINGTON, INDIANA.

ROTARY STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 552,992, dated January 14, 1896. Application filed May 29, 1894. Serial No. 512,936. (No modelfii To all whmn it may concern.-

Be it known that I, \VILLIAM Lnwis Evans, J12, a citizen of the United States, residing at Vashington, in the county of Daviess and State of Indiana, have invented a new and useful Rotary Stean1-Engi.ne, of which the following is a specification.

My invention relates to rotary steam-engines of the type known as eccentric piston and it has for its obj cct to provide a simple and direct-acting construction in which the journals are relieved of the weight of the piston, and, furthermore, to provide improved means for packing the joints between the surfaces of the moving parts to prevent loss of energy by leakage.

Further objects and advantages of the invention will appear in the following description, and the novel features thereof will be particularly pointed out in the appended claims.

In the drawings, Figure 1 is a perspective view of a rotary engine embodying my invention. Fig. 2 is a central section of the same, taken upon a plane at right angles to the axis of the piston. Fig. is a vertical central section taken in a plane parallel with and through the axis of the piston. Fig. -l is a detail view, in perspective, of a set of packing-strips. Fl 5 is a similar view of the same, with the parts detached. Fig. 6 is a face view of one end of the piston. Fig. 7 is a horizontal section of the controlling-valve and casin g. Fig. 8 is a section through one of the packing-segments.

Similar numerals of reference indicate corresponding parts in all the figures of the drawings.

l designates the cylinder having the heads 2, provided with journals for the spindle at of the piston 5, said j ournals being arranged eccentrically in the cylinder and preferably above the center thereof, whereby the pressure of steam upon the piston is upward and thus relieves the journals of a portion if not all of the weight thereof. The piston coinprises a core 6 and spaced heads 7, arranged radially in channels 8 formed in the core. These heads each comprise twin strips arranged in juxtaposition, with their inner or contacting surfaces grooved, as shown at 8, and provided with hooks 9, with which are engaged the extremities of a coiled spring 10. The spring occupies said grooves in the inner surfaces of the strips, and the tension thereof extends the strips in opposite directions toward the heads of the cylinder, whereby their extremities are held in steam-tight contact therewith during the operation of the engine.

The eccentricity of the piston is sufficient to cause one side of the core or body thereof to contact, approximately,with the side of the cylinder, and in order to insure the radial extension of the piston-heads '7 at that side of the piston which is separated from the cylinder I employ. plate-springs 11, which bear against the inner edges of the strips forming the heads, and are held in place by small plates 12, fitted in the channels in the core. These plates are in turn held in place by spacing-pins 13, fitting slidably in radial perforations or sockets 1i, intersecting the axis of the core. lVhen one of the piston-heads is at that part of the core which is in contact with the wall of the cylinder and is repressed wholly within the channel which forms its seat, the opposite head is correspondingly ex tended to close the space between the opposite side of the core and the separated. wall of the cylinder, and thus form an abutment for the steam.

The controlling-valve 15 .in the construction illustrated in the drawings is of the plug type, and is fitted in a casin g 16, provided with four radial communicating pipes. The diametrically-opposite pipes 17 and 18 communicate, respectively, with cavities 19 and 20, formed in the inner surface of the wall of the cylinder at dianietrically-opposire sides thereof, said cavities being increased in depth toward their upper ends, and the diametricallyopposite pipes 21 and 22 are adapted for attachment, respectively, to inlet exhaust steam pipes, and in the following description will be referred to as such. The plug is provided with opposite flattened portions, whereby the steanrinlet pipe may be arranged in communication with either conducting-pipe 17 18, and at the same time the exhaust-pipe is connected with the other conductingpipe to enable the engine to be reversed.

The shallow cavities in the opposite sides of the cylinder allow a more effective appli- ICO cation of the steam to the piston-heads at one side and a more ready exhaust at the opposite side.

Grooves 23 are formed in the ends of the piston-core, and therein are seated packingsegments 24:, held extended by subjacent coiled springs 25, arranged in suitable sockets 26, and suitable stuifing-boxes are provided at the outer ends of the bearings in the cylinder-heads.

The cylinder-heads are further provided around the bearings therein with annular oil'- wells 27, communicating by radial ducts 28 with the bearings and by similar ducts 29 with the interior of the cylinder to feed oil to the ends of the piston-core, and a vertical feed-duct 30 communicates with each oil-well and is fitted with an oil-cup 31. An oil-cup 232 communicates witha duct 33, formed in the upper side of the cylinder, and a blow-off 34 is arranged at the lower side of the same for purposes which will be readily understood.

The operation of the improved mechanism Will be readily understood from the foregoing description, and it will be obvious that the same construction may be used in connection withhydraulic motors, force-pumps, exhaustfans, air-pumps, and similar devices, and that various changes in the form, proportion, and minor details of construction maybe resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

Having thus described my invention, I claim 1. In a rotary engine, the combination with a cylinder having inlet and exhaust ports, of a piston having a head adapted to bear at opposite ends against the surface of the cylinder and comprising parallel overlapping strips adapted to slide in opposite directions in con- 1 tiguous planes, and a spring interposed between and concealed by the strips, and connected at its extremities thereto to cause pressure of the strips in opposite directions, substantially as specified.

2. In a rotary engine, the combination with a cylinder provided with inlet and exhaust ports, of an eccentric-ally mounted piston hav ing a core provided with radial seats, and piston-heads fitting in the seats and comprising twin juxtaposed strips and interposed springs connected at their extremities, respectively, to the strips, whereby the latter are extended in opposite directions to form steam -tight joints with the heads of the cylinder, substantially as specified.

3. In a rotary engine, the combination with a cylinder provided with inlet and exhaust ports, of an eccentrically mounted piston having a core provided with radial seats and piston-heads fitting in the seats and comprising twin juxtaposed strips arranged in parallel planes with their inner ends overlapping to break joint and provided in their facing sides With longitudinal cavities and termin al hooks, and contraction springs arranged in said cavities and engaged at their extremities with said hooks, whereby the strips are extended in opposite directions to form steam-tight joints with the heads of the cylinder, substantially as specified.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

\VILLIAM LEIVIS EVANS, J R.

Witnesses DAVID J. TOMEY, EDWARD \VEEKs. 

